Auto pilot failures on multihulls

[latitude_zero]

Hey guys, been looking into buying a boat... Have been leaning toward a multihull but wanted to ask. On long crossings have many of you guys had auto pilot failures? What's the backup plan? What's the typical failure point?

-Jason

[andreas.mehlin]

Have a spare one just in case. If you have a linear drive, one option is to have a wheel or tiller pilot as backup.

[rabbi]

I had an older B&G AP fail on the transatlantic. One soldering point failed and had to be re-soldered in the middle of nowhere.

For another transatlantic I would take a simple self-contained tiller AP with me to jury-rig something that helps in case of failure.
Taking a complete AP as spare would not be feasible as a complete AP including hydraulic actuator costs a fortune.

[Cotemar]

This is are 2nd Fountane Pajot that we have taken across the Atlantic.
She just pulled into St. Martin this morning. Then north to Newport RI.
Autopilot all good so far.

[Mr B]

Never had a failure, But I have had the Autopilot drop out,
Which put me beam on to the waves, Instantly, Very scary, as I had both centre boards down and the lee side one dug in on the side of a very steep wave, almost rolling me over sideways, I was at about 70 degrees,
I just spun the wheel around and down the wave,
No I dont know why it dropped out,
I now keep the Leeside Centre board up when travelling, and the windward side down,

Second time it happened, I was doing 8 knots forwards, actual, 5 knots sideways drift, The GPS was was telling me 1.5 knots and going round in circles, I think it was lost, and then dropped out, I also had a strong sea current running,
No idea personally, as I wasnt experienced enough to know what was going on, It was all new to me,
The compass was set due west, and thats what I went by, I just kept going west,
About 25 Nmiles later, I was out of the currents and it all returned to normal,

I also carry a spare Autopilot Complete, But it is a part of the steering, But I can manually steer if it does go Kaput,
The steering cables are the ones that will put you in the Poop, You need to carry a spare set of them,
Or what ever your steering wheel is connected to the rudders by,

[tomfl]

The dirty secret of any AP is that the amount of work it does (and by extension how easily it will fail) is inversely related to how well the boat is able to be, and is, balanced. I have no problem trimming my sails on many points of sail (in a consistent wind direction and speed) so my boat will hold a course with out an AP. On the other hand on some points of sail on a particular course the boat will try and round up or fall off no matter how the sails are trimmed even with the AP in use.

Another consideration is wave action. Surfing down the face of a wave increases boat speed and moves the apparent wind forward while climbing up the face of a wave decreases boat speed and moves the apparent wind aft; in both cases the AP or person at the helm will most likely need to make a correction.

These factors, and probably others as well, make it impossible to estimate AP failure. There are simply some times that no matter the boat, heading, or AP it is necessary to have a skilled person at the helm. On the other hand under different conditions the AP on a well trimmed boat will be doing no, or almost no, work and there is minimal chance of failure.

Bottom line is if your can trim your sails to get your boat to hold a course your AP will last a lot longer than if your boat has problems holding a course no matter how you try and balance it.

[Bulawayo]

Originally Posted by latitude_zero

Hey guys, been looking into buying a boat... Have been leaning toward a multihull but wanted to ask. On long crossings have many of you guys had auto pilot failures? What's the backup plan? What's the typical failure point?

-Jason

We've never lost an autopilot (and cruised since '95) - some say we are lucky but we are cautious. Our autopilots (both fitted) are over sized and identical to allow for cannibilsation. The finances did not factor .....can you afford not to have an alternative?

[Pieter]

Our AP broke down 4 days before arriving to the Azores on our Atlantic Crossing. The failure was in the actual onboard computor/electronic cirquit. I was able to get this part (new) in Lisbon. Could have been avoided? Yes, i guess so.. this part is neatly tucked away in the space beneath the cabine/matress. Moisture built up and prob salt water had been trickling down and so oxidating/deteriorating the electronic plates/boards to the point they just melted down. Now, i regularly check the condition and believe this issue wont repeat it self. Actualy, this issue is not relevant for only multihulls, it could have happened easily on a monohull as well.
Best rgds
Pieter Kommerij
SV Lumina
Lumina Charters – Brazilian Coastal Catamaran Sailing

[svrevelations]

Coincidence that we are asking at the same problem. We had an autopilot failure on a recent cross ocean voyage which we could not repair at sea. We had to hand steer for almost 2 weeks - tiring and not pleasant. It later emerged that the electric motor seized. We are now looking for a back up solution;

http://www.cruisersforum.com/forums/...ml#post2147162

[captstu]

I carry a spare wheel pilot on deliveries. Not hard to put on And not very expensive. It won't auto steer all the time but as others of pointed out when the boat is nearly trim perfectly it will steer for hours and give me a break.

Unfortunately I broke the cable delivering a boat that it been hit by lightning weekend the cable while I was out on a delivery. Was able to rig manual steering Using the remote tillers but no autopilot.

Just went ensure was lucky to be nearby.

[Double-Wide]

On a delivery trip from Key West across the Gulf to Galveston we lost the autopilot on our Seawind 1160 about 2 hours outside Key West. The cause was a can of coke that accidentally spilled right next to the autopilot control head. Lesson learned no soft drinks near the instruments.

Our only alternative was to hand steer the entire voyage.


Sent from my iPad using Cruisers Sailing Forum

[Lepke]

An autopilot is like having another crew member 24/7. When I was commercial fishing, most had Wood-Freeman pilots, known as Iron Mike. Mine was at least 30 years old when I bought the boat and still working when I sold it. Newer pilots need less power and have nice features, but reliability isn't one of them.
On 12 volt systems good contacts and proper wire size to the pump makes a difference. I run oversize wire and solder my terminals after crimping. Corrosion loves crimped terminals. As resistance grows, more amps are needed, eventually burning contacts, the motor or circuit boards.

[peter57]

Would be a good solution for someone to design a wind vane steering system for sailing rafts.

[Palarran]

Oh, Peter, you are so funny!! Even with the whistling smiling face that was a special funny that only multihull posters on this forum can appreciate.

I think Tom nailed it. Don't overwork the AP and it will keep going. Mine is 16 years old now and in the past 7 that I've owned the boat has worked flawlessly.

[Captain Bill]

Oddly enough I just had my first autopilot failure on my 14 year old cat. Fortunately it happened at the dock. The shaft seal on the hydraulic pump let go and dumped all of my hydraulic fluid all over my mechanical room and the stuff I had stored in it. Quite a mess and it left me with no manual steering either, so here I sit waiting for a new pump. I'll replace the seal in the old one and have it as a spare. I will also rig it so I can Isolate the pump from the manual system. I carry a rebuild kit for the cylinder and the manual pump connected to the wheel. I replaced my old st5000 last year with a modern Raymarine autopilot; The new one was able to use the old rudder position indicator and I connected my old fluxgate compass as well. The ST5000 is a pretty simple minded beast and can function with a fluxgate compass and a rudder position sensor for holding a course. The computer is contained completely in the control head so all I have to do to install it is connect the power, and move the spade connectors for the compass, rudder sensor and hydraulic motor control and I'm operational again. If I connect it to my seatalk to seatalkNG adapter I have full function. So having a spare pump and the old ST 5000 I'll have a full backup with minimal storage requirements. It sure beats manual steering,